Bill Cosby once said, “A father knows exactly what those boys at the mall have in their depraved little minds because he once owned such a depraved little mind himself.”

Fathers are merely grown-up versions of those boys in the mall. Good fathers, however, are men who have mastered their youthful depravity and now help their sons – and daughters – overcome their own.

Father’s Day celebrates the unique love and life perspective – you might call it “mall knowledge” – only a father can give his children.

Amid the clamor to erase gender differences – and modern sitcoms’ penchant for portraying dads as befuddled boys in grownup bodies – Father’s Day reminds us that kids still need their dads. A daughter needs her dad to model how a good man should treat her. A son needs his dad, who is uniquely suited to help him become the good man who will one day put his wife and children’s best interests ahead of his own “mall interests.”

The best mom in the world cannot be a good dad, because she was never one of those boys in the mall. Science, as well as intuition, tells us men and women are inherently different. Consequently, as Dr. Kyle Pruett of Yale Medical School wrote in his book “Fatherneed,” “fathers do not mother.”

Doubling a child’s number of moms or dads cannot compensate for the unique role each opposite-sex parent provides in a natural family. Two moms may be able to double a child’s dose of mother-love. But, even together, as numerous studies have found, they cannot bring into that child’s life that unique male perspective.

While mothers are naturally more gentle and nurturing with their children, as Dr. Pruett’s book points out, fathers “love more dangerously.” Fathers tend to encourage their children to take chances, to explore new vistas. Kids need a healthy dose of both kinds of love.

That some men have failed to fulfill their role as good fathers does not justify opening the time-tested familial roles to additional experimentation. The easy-divorce experiment, for example, has scarred millions of children. Dr. Mavis Hetherington of the University of Virginia, widely considered to be among the nation’s leading experts on divorce, wrote, “divorce is brutally painful to a child.”

And, statistically, a child’s odds for happiness and safety do not get much better in a post-divorce stepfamily. According to an article in the American Association of Pediatricians journal Pediatrics, “stepparenthood” is the single most powerful risk factor for child abuse.

Ironically, in the very same issue of that journal, AAP also published a report claiming no discernable differences among children raised in heterosexual homes and those raised in same-sex-parenting homes. But that AAP study, which had several design flaws, compared kids raised in same-sex-parenting homes to children raised in heterosexual stepfamilies, rather than to kids raised with their natural parents. Essentially, the study compared two types of step-parenting while ignoring the more natural family.

Same-sex parents are no more inherently evil than are stepparents or natural parents. All are prone to human failures. But the statistical facts remain: Children raised in natural mother-father families do best by virtually all health and social standards.

Those boys in the mall need the best available odds to help them overcome their depravity and in turn become good fathers. They’ll have the best odds in a stable family, led by their natural mother – and father.

Glenn Stanton is the senior analyst for marriage and sexuality for Focus on the Family. He is the author of “Why Marriage Matters” and co-author of “Marriage On Trial: The Case Against Same-Sex Marriage and Parenting”. His work is available at focusonsocialissues.com.